1. Field of the Invention
The present invention relates to a sheet-type detection device for detecting the thickness and surface roughness of recording sheets made of different types of materials such as paper, nonwoven fabric, and plastic film.
2. Description of the Related Art
Known data recording devices record and output data, such as image data, at high definition. Therefore, only predetermined types of recording sheets, such as sheets of specialized paper suitable for recording data by electrography, could be used for data recording devices.
Since toner, ink, and photoreceptors have been improved, data recording on various types of commercially available multi-purpose paper has become possible.
However, to record data on various types of recording sheets, data processing parameters, data recording conditions, such as conditions for fixing and transferring an image, and mechanical control conditions, such as conditions for sheet delivery, have to be suitable for the type of sheet. In order to set suitable conditions, the various types of recording sheets have to be categorized.
The thickness of a recording sheet is inputted through a user interface of an operating unit or a hard switch. The conditions concerning the data recording process, such as a target temperature for the temperature control of the fixing unit, is determined in accordance with a code defining the thickness of the recording sheet (for example, refer to Japanese Patent Laid-Open No. 6-348095).
The above-described data recording device first requires the thickness of the recording sheet to be inputted by operating an external unit or a switch. This operation is too complicated to be carried out by all users.
Furthermore, if a wrong code is inputted by a user, the data recording device records data in accordance with the wrong code and often causes damage to the device. As a result, significant losses, such as an increase in the downtime of the device and repairing cost, arise.
More specifically, if the data recording device is set for recording on a thin recording sheet but a thick recording sheet is used for the actual recording, the thick recording sheet will be delivered to the photoreceptor and fixing unit at a speed faster than normal. As a result, the impact of the recording sheet entering the photoreceptor and fixing unit may damage the data recording device.
Even if a wrong setting does not cause damage to the data recording device, the wrong setting may cause unsuccessful delivery and unsuccessful fixing of the recording sheet. This may cause jamming of the recording sheet that leads to unsuccessful data recording. As a result, the user will be significantly inconvenienced.
Recently, recycled paper has been in heavy use. In addition to recycled paper, various needs of users have led to the introduction of coated paper having coated surfaces and Leathac and embossed paper having surfaces with many irregularities. Such different types of special recording paper are characterized by their thickness and surface roughness.
Conditions and settings of the data recording process, including fixing and transferring processes, and conditions of mechanical control, such as sheet delivery, must be changed in accordance with the surface roughness of the recording sheet. For this reason, it has become even more important to categorize recording sheets according to the type of material the recording sheet is made of.
Inputting data recording conditions through a user interface or a hard switch, as described above, requires complicated operations that can easily lead to incorrect input.